I use a down comforter bought at Costco. It folds into a small clear bag (the one it came in) and fluffs out nicely. It keeps us snug in 30 degree temps and not excessive in the summer. We've had for years. Liked it so much, I bought a smaller down throw for covering my lap in the evening....but then the Snuggie came along and I cozy down with that when reading my Nook prior to bed...DH uses the smaller lap blanket for himself when relaxing inside.
2012 FR Flagstaff T12SDTH
1996 Shadowcruiser Pop Up Truck Camper
1967 Newell Motorcoach
2003 Ford F150 5.4 V8 Triton Super Cab
2004 Nissan Titan LE 5.6 V8 4x4 Crew Cab